ZOOLOGISCHE MEDEDELINGEN

ZOOLOGISCHE MEDEDELINGEN UITGEGEVEN DOOR HET RIJKSMUSEUM VAN NATUURLIJKE HISTORIE TE LEIDEN (MINISTERIE VAN WELZIJN, VOLKSGEZONDHEID EN CULTUUR) Deel 61 no. 30 29 december 1987 ISSN 0024-0672 RADFORDIA (RADFORDIA) DALTONI SPEC. NOV. (ACARINA: PROSTIGMATA: MYOBIIDAE) FROM PRAOMYS (MYOMYSCUS) DALTONI (MAMMALIA: RODENTIA: MURIDAE) by G. SCHEPERBOER, F. S. LUKOSCHUS and A. FAIN Scheperboer, G., F. S. Lukoschus & A. Fain: Radfordia (Radfordia) daltoni spec. nov. (Acarina : Prostigmata : Myobiidae) from Praomys (Myomyscus) daltoni (Mammalia: Rodentia: Muridae). Zool. Med. Leiden 61 (30), 29-xii-1987: 431-442, figs. 1-10, tables 1-3. ISSN 0024-0672. Key words: Acarina; mites; taxonomy; Africa. Radfordia (Radfordia) daltoni spec. nov. ex Praomys (Myomyscus) daltoni is illustrated, described in detail, and compared with the related species Radfordia (R.) praomys Zumpt & Coffee, 1977, ex Praomys (Mastomys) natalensis (A. Smith, 1834) from South Africa, and Radfordia (R.) praomys trifurcata Fain, 1973, from the same host species from Ivory Coast. G.Scheperboer & F. S. Lukoschus 1, Department of Aquatic Ecology, Catholic University, Nijmegen, The Netherlands. A. Fain, Institut Royal des Sciences naturelles de Belgique, Bruxelles, Belgium. 1 Deceased on August 23, 1987. INTRODUCTION The co-evolution of mammals and host specific mites of the family Myobiidae has been discussed by Fain (1974,1979) and Fain & Lukoschus (1976, 1977). Related species of Myobiidae from closely related host species do not show very distinct morphological differences, however, smaller modifications 431 Zool. Med. Scheperboer 61-30 - Vel 1

432 ZOOLOGISCHE MEDEDELINGEN 30 (1987) of male genital region erect panmixis barriers, followed by deviating modifications of further characters. We describe a new species of Radfordia (Radfordia) from Praomys (Myo- Figs. 1-2. Radfordia (Radfordia) daltoni spec. nov., female holotype, 1) venter, 2) holotype dorsum.

SCHEPERBOER, LUKOSCHUS & FAIN: RADFORDIA DALTONI 433 myscus) daltoni (Thomas, 1892) that is compared with the closely related species Radfordia (R.) praomys Zumpt & Coffee, 1971, from the related host species Praomys (Mastomys) natalensis (Smith, 1834) and Praomys (Praomys) mono (Trouessart, 1881). Measurements are given in micrometers (μπι) for the holotype, allotype, and paratypes (Ν = number of specimens examined, χ = mean and range). DESCRIPTION OF SPECIES Radfordia (Radfordia) daltoni spec. nov. (figs. 1 10) Deposition of types. Holotype and allotype in U.S. National Museum of Natural History (Smithsonian Institution), Washington, D.C.,U.S.A., type collection nr. 3978; paratypes in Field Museum of Natural History, Chicago, Illinois, U.S.A.; The South African Institute for Medical Research, Johannesburg; British Museum (Natural History), London, 1980.8.26.18 23; Zoologisches Museum, Hamburg; Institute of Parasitology, Prague; Muséum National d'histoire Naturelle, Paris, 55F (12 15); Rijksmuseum van Natuurlijke Historie, Leiden; Institut de Médecine Tropicale Prince Leopold, Antwerp; Department of Aquatic Ecology, Catholic University, Nijmegen. Female (holotype): Length including gnathosoma 333, χ (N = 9) 359 (333 370), width 170, χ 173 (161 182). Cuticle transversely striated with exception of lateral parts of coxal fields I and of genital region. Venter (fig. 1): Present are in coxal fields I IV 4 3 1 1 coxal setae, on opisthoventer the setae d 5 and /5. All innermost coxal setae (ic 1 - ic 4) short. Measurements in table 1. Coxal field I with sclerotized, unstriated posterolateral spurs (VS). Dorsum (fig. 2): Setae v i, ν e relatively narrow, with a partial central core and one barb; setae sc i y sc e and /1 with two lateral barbs and a blunt to spatulate tip ; d 7, d 4,12 and / 3 setiform ; d 2 and d 3 slightly expanded ; setae / 4 not observed. Supracoxal setae of legs I (e I) between ν i and ν e. Genital region dorsoterminal, genital cone without cuticular pattern. Vulva (V) between relatively small vulvar valves, carrying setae ai y ae and small slightly curved a 3 (genital hooks). Bursa copulatrix and duct to vulva not observed. Genital opening terminally with four pairs of genital setae (g 2 absent). Gnathosoma sub oval in shape, with small rounded latero ventral spurs (GH) and the usual setation (r a, rp, r d) and supracoxal setae (ep). Palps two segmented, each segment with one small seta. Legs with sub genus' typical shape and setation (setae of

434 ZOOLOGISCHE MEDEDELINGEN 30 (1987) Table 1: Comparison of body and setal measurements between femalesofradfordia (Radfordia) daltonispec. nov., R. (R.) praomys Zumpt & Coffee, 1971, and R. (R.) praomys trifurcata Fain, 1973. Data from Zumpt & Coffee (1971) and Fain (1973). daltoni praomys trifurcata holotype paratypes 3 paratypes from description (Ν = 9) and figure χ min.-max. length 333 359 (333-370) 374 (364-382) 375 width 170 173 (164-182) 206 (200-216) 186 cxv (ic 1) 15 14 ( 12-16) 16 ( 16-17) cxp 21 19 ( 17-21) 23 ( 16-17) cxp 21 20 ( 18-21) 23 ( 23 ) cx I 4 12 13 ( 12-15) 16 ( 16 ) ν i 38 39 ( 26-42) 46 ( 42-50) 41 ν e 60 57 ( 50-62) 62 ( 60-63) 75 sc i 60 59 ( 55-65) 65 ( 65-66) 69 sc e 74 74 ( 71-79) 78 ( 77-78) 90 dl 51 47 ( 43-50) 63 ( 61-67) 69 d2 79 79 ( 73-83) 82 ( 79-84) 96 d3 65 68 ( 63-71) 73 ( 60-81) 95 11 57 59 ( 55-63) 72 ( 68-74) 72 15 273 280 (267-291) 297 (285-303) width ν ι 2 2 ( 2 ) 2 ( 2 ) ν e 6 6 ( 6 ) 7 ( 7 ) sc i 2 2 ( 2 ) 2 ( 2-3) sc e 2 2 ( 2 ) 2 ( 2 ) dl 2 2 ( 2 ) 3 ( 2-3) d2 4 4 ( 4 ) 6 ( 5-6) above 7 d3 5 4 ( 4-5) 7 ( 6-7) above 8 fused segments tarsus - tibia - genu of legs I not counted) : tarsi -,7,6,6; tibiae -, 6,6,6; genua -, 7,6,5; femora 6,5,3,3; trochanters 3,3,3,3; claws 0,2,1, 1. Legs I with small trochanteral spurs (TS) on ventral side. Trochanters III and IV each with a setiform dorsal seta, shorter than length of legs. Male (allotype): Length 267, ten paratypes χ 262 (248-263), width 142, in paratypes χ 141 (127-152). Venter (fig. 3) similar to female, with position of /5 and suppression of d 5 like in other males of subgenus. Dorsum (fig. 4) with genital region between level of sc e and /1. Setae ν i, se i, and opisthosomal setae short, setiform; setae ve, see and /1 with only one lateral barb. Genital

SCHEPERBOER, LUKOSCHUS & FAIN: RADFORDIA DALTONI 435 Figs. 3-4. Radfordia (Radfordia) daltonispec. nov., male allotype, 3) venter, 4) allotype dorsum. opening (fig. 10, GO) on a short, parallel-sided tubercle, with conical end between two pairs of semi-tubular genital setae, which probably serve to guide the aedeagus. Aedeagus linear, well sclerotized, directed anterad, 67 long. Setae dl,d2 barbed, laterad of genital tubercle. Gnathosoma and legs similar to female, with exception of absence of trochanter I spurs, and strong, blunt

436 ZOOLOGISCHE MEDEDELINGEN 30 (1987) Fig. 5. Radfordia (Radfordia) daltoni spec. nov., prelarva.

SCHEPERBOER, LUKOSCHUS & FAIN: RADFORDIA DALTONI 437 shape of md setae on tarsi I and II (like in all males of genus). Measurements in table 2. Development stages Eggs: 194 long, 66 wide, lice-like attached to hairs of host, chorion smooth. Praelarva (fig. 5): Cryptostatic within the egg. Cuticle with transverse striations. Anteriorly are present dorsally two spearhead-shaped, strongly sclerotized structures, ventrally a funnel-shaped opening and associated sclerotized duct. Larva (fig. 6): Length of four specimens χ 195 (161-222), width χ 108 (94-122). Present are setae e 1> v e y ν i, sc e y se i, d 1, 2, 3, 5,11,3,5 and one pair of anals on dorsum; ic 1 ventrally. Vertical setae shifted backwards far behind level of legs II. Propodonotal setae short, setiform with blunt tip, partly with Table 2: Comparison of body and setal measurements between males of Radfordia (Radfordia) daltoni spec. nov. and R. (R.) praomys Zumpt & Coffee, 1971, ex Mastomys natalensis and Praomys morio. Radfordia (R.) daltoni R. (R.) praomys ex Myomyscus daltoni Mastomys Praomys natalensis morio allotype 10 paratypes 2 specimens 2 specimens length 267 262 (248-273) 285, 291 242, 255 width 142 141 (127-152) 164, 170 133, 145 cx I 11 12 ( 10-12) 11, 13 13, 13 cx I 15 16 ( 15-17) 16, 18 17, 17 cx I 15 16 ( 13-18) 17, 20 17, 17 ν i 12 12 ( 11-12) 12, 13 11, 12 ν e 59 57 ( 51-60) 61, 68 56, 59 sc i 12 14 ( 10-15) 18, 20 16, 16 sc e 81 80 ( 76-82) 84, 89 81, 81 dl 7 8( 7-9) 6, 6 5, 5 d2 10 10 ( 10-12) 9, 9 6, 6 11 84 85 ( 79-90) 92, 93 94, 95 15 285 271 (255-285) 291, 297 279, 291 width sc e 2 3( 2-4) 2, 4 2, 2 11 3 3( 2-4) 4, 4 4, 4

438 ZOOLOGISCHE MEDEDELINGEN 30 (1987) Figs. 6-7. Radfordia (Radfordia) daltoni spec. nov., 6) larva dorsum, 7) protonymph dorsum.

SCHEPERBOER, LUKOSCHUS & FAIN: RADFORDIA DALTONI 439 Figs. 8-9. Radfordia (Radfordia) daltoni spec. nov., 8) deutonymph, dorsum, 9) tritonymph, dorsum.

440 ZOOLOGISCHE MEDEDELINGEN 30 (1987) small barb. Hysteronotal setae with spatulate tips and short, triangular transparent broadening on basal part of seta, suggesting two-segmented shape of seta (see detail figure). Gnathosoma and legs I similar to those of other species of subgenus. Legs II, III four-segmented. Solenidion sigma (so) indicates fusion of genu and femur. Chaetotaxy legs II, III: tarsi 7-4, tibiae 3-3, genufemora 1-1, trochanters 0-0. Strong claw on praetarsus II, small claw on III. Protonymph (fig. 7): Length 185, width 106. By suppression of legs IV to the shape of small, rounded, lateral protuberances resembles larva; however, protonymph-typical setation of coxal fields I-IV is present: 2-1-1-0. Propodonotal setae in same position as in larva; sc e stronger and typically prolonged. Setae d 1-d 3 shifted to level of legs IV. Setae d 4, d 5, 11 and / 3 suppressed. Deutonymph (fig. 8): Length in nine specimens 207 (192-288), width 134 (127-170). General shape like protonymph, with legs IV. Chaetotaxy of legs II-IV: tarsi 7-5-0, tibiae 4-3-0, genu-femora 1-1-0, trochanters 1-1-0, coxal fields I-IV 2-1 -1-1. Tritonymph (fig. 9): Length of 15 specimens 274 (236-333), width 168 (145-206). General shape like deutonymph, with legs IV nude, three-segmented. Dorsal setae longer and more modified (see table 3). Added is a second pair of anal setae. Chaetotaxy of legs II-IV: tarsi 7-6-0, tibiae 5-3-0, genu-femora 2-1-0, trochanters 1-1-0, coxal fields I-IV 3-2-1-1. Measurements in table 3. Host and locality. Praomys (Myomyscus) daltoni (Thomas, 1892), Safari Lodge, Comoe N.P., Ivory Coast, 15-III-1979, 18-III-1979, leg. Christian F. Weisser, present depository unknown. Comparison with related species. Radfordia (Radfordia) daltoni spec. nov. is closely related to R. (R.) praomys praomys Zumpt & Coffee, 1971, and R. (R.) praomys trifurcata Fain, 1973. The setal measurements of the species Table 3: Setal measurements of the immatures of Radfordia (Radfordia) daltoni spec. nov. larva protonymph deutonymph tritonymph Ν 1 1 9 15 ν e 2 6 10 ( 6-14) 17 ( 13-21) sc e 3 46 62 ( 54-67) 97 ( 85-109) dl 9 10 12 ( 10-13) 19 ( 17-24) d2 9 16 28 ( 21-35) 55 ( 49-63) d3 8 18 28 ( 20-30) 40 ( 37-44) 15 145 134 189 (170-198) 209 (200-224)

SCHEPERBOER, LUKOSCHUS & FAIN: RADFORDIA DALTONI 441 Fig. 10. Comparison between setae 11, d 2 and d 3 of females, and the male genital regions of Radfordia (Radfordia) daltoni spec. nov. and Radfordia (R.) praomys Zumpt & Coffee (1971). are compared in tables 1 and 2. In females only the length of /1 and the width of setae d 2 and d 3 are significantly different (comparison in fig. 10). Males can be separated by the shape of the genital cone and genital setae (fig. 10); significant differences in length of setae are present only in d 1 and d 2. The current concept of R. (R.) praomys praomys parasitizing hosts of different genera (subgenera) of the Praomys(-group) should be re-examined. We may expect, that they will be parasitized rather by related (sub-)species. In their study of Radfordia (R.) petromyscus Lukoschus et al. (1981) have

442 ZOOLOGISCHE MEDEDELINGEN 30 (1987) given some characters of Radfordia (Radfordia) species in tabulated form. According to them R. (R.) praomys is the only species of the subgenus Radfordia from Muridae hosts with the combination of coxal setae 4 3 1 1 with all innermost coxal setae short. The observation of the nymphal stages with pression of the lateral setae, and suppression of d 5 after having been present in the larval stage, in the species and subspecies from Praomys hosts is unique in the subgenus Radfordia. Similar pression of setae, and of d5 after presence in larval stage are present in all genera and species from Insectivorous hosts (exception Suncomyobia and Nectogalobia because of lacking larvae in collection). ACKNOWLEDGEMENTS We are grateful to Dr. Christian F. Weisser, Zoologisches Institut, Heidelberg, for the loan of alcohol preserved Praomys (Myomyscus) daltoni specimens for observation. REFERENCES Fain, Α., 1973. Notes sur la nomenclature des poils idiosomaux chez les Myobiidae avec description de taxa nouveaux (Acarina: Trombidiformes). Acarologia 15: 289 309. Fain, Α., 1974. Observations sur les Myobiidae parasites des Rongeurs. Evolution parallèle Hôtes Parasites (Acariens: Trombidiformes). Acarologia 16: 441 475. Fain, Α., 1979. Specificity, adaptation and parallel host parasite evolution in Acarines, especially Myobiidae, with a tentative explanation for regressive evolution caused by the immunological reactions of the host. In: Recent advances in acarology, 2: 321 328. Ed. J. G. Rodriguez. Academic Press, New York. Fain, A. & F. S. Lukoschus, 1976. Observations sur les Myobiidae d'insectivores avec description de taxa nouveaux (Acarina: Prostigmates). Acta Zoologica et Pathologica Antverpiensia 66: 121 188. Fain, A. & F. S. Lukoschus, 1977. Nouvelles observations sur les Myobiidae parasites de Rongeurs (Acarina: Prostigmata). Acta Zoologica et Pathologica Antverpiensia 69:11 98. Lukoschus, F. S., J. H. A. J. Curfs & A. Fain, 1981. A new fur mite (Acarina: Prostigmata: Myobiidae) from the South African Rock Mouse Petromyscus collinus. Bulletin de ltnstitut royal des Sciences naturelles de Belgique, Entomologie 53 (25): 1 8. Zumpt, F. & G. Coffee, 1971. The genus Radfordia in the Ethiopian Region, with descriptions of two new species (Acarina: Trombidiformes: Myobiidae). Annals of the Natal Museum 21 (1): 97 105.